Abstract: The present disclosure relates to an isolated PD-L1 antibody whose binding to PD-L1 at acidic pH is substantially lower than its binding to PD-L1 at neutral pH at the same assay setting and an isolated PD-L1 antibody that is not pH dependent in binding to PD-L1. Also provided is the pharmaceutical composition of the antibody, encoding polynucleotide and expression vector, isolated host cell thereof as well as a kit comprising the PD-L1 antibody. Also provided herein are methods of treating a PD-L1 associated condition using the PD-L1 antibody.